Error Provider Control in Windows Forms

When using validation, programmer should have notify a message if there is a problem with the input entry. That notification can be shown using message box, status label control etc. The one more control to notify an error message to user is error provider control.

Error provider control can be used to display an error message, whenever the user positions the mouse pointer over the error icon. To add an error provider control, you can drag-n-drop it from the toolbox to the form. Some of the properties of this control are:

• BlinkStyle: whether the error icon blinks or not when an error is set.
• BlinkRate: rate at which the error icon blinks.
• ContainerControl: contains the controls on which this control can display icons.

Here are some methods which are mostly used with error provider:

• Clear(): clear all the errors associated with it.
• GetError(): returns current error string for the specified control.
• SetError(): set the error for specified control.

To set an error for a textbox when user left empty, drag-n-drop a textbox, button and an error provider control on a form. On the click event of button write following code in C# language:

if (textBox1.Text == string.Empty)
{
textBox1.Focus();
errorProvider1.SetError(textBox1, "This may not be Empty");
}

When we run the form and click on the button without writing anything in the textbox, then an error icon will blink just after the textbox with a message shown as a tool tip of the icon.

Here in the code a method SetError() have been used, it takes two parameters, one for the control (to which error will be associated) and the second for the message to be shown. A single error provider can easily be used with more than one control.

Status Strip Control

XNA Game : SquareChase

The Basic Aim of the Game
In SquareChase , we will generate randomly positioned squares of different colors while the user attempt to catch them with their mouse pointer before they disappear .

System requirements of the project
First you need to install visual c# 2010 and XNA framework extensions.Your system has support graphics card (Shader Model 1.1 Support, Direct X 9.0 support)

How to design the game
First you need to initialize the graphics object in your XNA Game class constructor.

graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";

Make the mouse pointer visible by adding the following before the call to 

base.Initialize();

this.IsMouseVisible = true;

here is the one override Initialize()  method is to call LoadContent() when the normal initialization has completed. The method is used to read in any graphical and audio resources your game will need.

Screenshot of the game

Project Source code

https://docs.google.com/file/d/0B7rTHuXc1VUjWVNVWDVXTTVONWs/edit?usp=sharing

Status Strip Container Control in Windows Forms

StatusStrip container control is used to display objects that are on the current form and also to provide feedback on the progress of any progress of any operation being performed by the form. Some of the properties of this container control are:

• Items: collection of items to be displayed on the control.
• LayoutStyle: specifies the layout orientation of the control.
• Dock: defines the border of control which will bind to the parent control.

Status strip control contains four child controls that can be placed as and when required. The child controls are:

Status Label Control

Works as a Label control. Used to display status information and prompt the user for a valid entry. It has some properties to be used by programmer like

• Text: text to be displayed on the control.
• Spring: whether the item fills up the remaining space or not. It is a Boolean type property.
• TextAlign: specify the alignment of the text.

ProgressBar Control

Used to show the status of the task performing by the user. Represent window progress bar control. Some properties of this control are:

• Minimum: lower bound of the range.
• Maximum: upper bound of the range.
• Value: current value to be set on this control.
• Step: value to be increment/decrement.

DropDown Button Control

Displays toolStripDropDown from which user can select one item at a time. Generally used when the items to be displayed on StatusStrip cannot be accommodated. Some of the properties of this control are:

• DisplayStyle: whether the text or image to be displayed.
• DoubleClickEnabled: whether the double click event will occur.
• DropDownItems: specifies the toolStripItem when the item is clicked.

SplitButton Control

It is a combination of a standard button and a drop-down button on the left and right respectively. Some of the properties are:

• DisplayStyle: whether the text or image to be displayed.
• DoubleClickEnabled: whether the double click event will occur.
• Padding: internal spacing within the item.

The following image shown all the four controls of the StatusStrip control.

Error Provider Control

ASP.NET : How to use Link Button control

The LinkButton control is another standard Web server control used to link the current Web page to some other Web page, similar to the HyperLink control. The only difference between the two is that the HyperLink control just allows the browser to navigate to a new Web Page, whereas in the LinkButton control, we can also perform some other action by handling the click and Command events of this control.

Use of the LinkButton control

• Best use in Signin/Signout button
• Design horizontal/vertical menu bar 
• In bulleted list 
• Define product category

Snapshot of the link button control

SignOut Example of LinkButton

<%@ Page Language="C#" %>
<!DOCTYPE html>

<script runat="server">

    protected void LinkButton1_Click(object sender, EventArgs e)
    {
        Session.Abandon();
        Response.Redirect("Default.aspx");
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:LinkButton ID="LinkButton1" runat="server" OnClick="LinkButton1_Click">SignOut</asp:LinkButton>
    </div>
    </form>
</body>
</html>

Output

Passing Values from DataGridView between Different Forms

Sometimes we need to transfer all the rows and columns of a DataGridView from one form to another. In this article I will transfer all the binded data of first form's grid view and bind them to second form's grid view.

Create two forms with dataGridView in each and a button on first form. Create a class to which your datagridview will bind like i create a student class having Name, Age and address field.
Bind the first form's gridview in C# language as

studList.Add(new Student() { Name = "Jacob", Age = 23, Address = "London" });
studList.Add(new Student() { Name = "Jaklin", Age = 25, Address = "US" });
studList.Add(new Student() { Name = "Julia", Age = 26, Address = "UK" });
dataGridView1.DataSource = studList;

In the click event of button write the following code in C# language

List<Student> tempList = dataGridView1.DataSource as List<Student>;
new Form1(tempList).ShowDialog();

And your second form's constructor have to look like the below code in C# language

public Form1(List<Student> sourceList)
{
InitializeComponent();
dataGridView1.DataSource = sourceList;
}

When we run this project and click on transfer button then both the form have same list of data e.g.

So we have passed all the rows and columns of first form's gridview to second form's gridview.

Windows Store Apps : Write simple Hello world

Getting started with windows store
Step-1: Download windows 8 sdk from Microsoft website
http://msdn.microsoft.com/en-us/library/windows/desktop/hh852363.aspx

Step-2: Select Windows store Apps from file-->New-->Project-->Visual C# -->Windows store

Step-3: Select "MainPage.xaml" file in solution explorer.

You can make use of the TextBlock control for displaying Text on the screen.The TextBlock control has a property called Text that you can set to "Hello World" after press button.

Step-4: Paste this code into your "MainPage.xaml" file


 

<Page
x:Class="Helloworld.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Helloworld"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
<Button Content="Press Me" HorizontalAlignment="Left" Margin="94,76,0,0" VerticalAlignment="Top" Width="192" Height="71" Click="Button_Click_1"/>
<TextBlock x:Name="label1" HorizontalAlignment="Left" Margin="94,175,0,0" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Height="85" Width="211"/>

</Grid>
</Page>

Codebehind file

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;




// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238
  
namespace Helloworld



{
  /// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page


{
  public MainPage()



{
  this.InitializeComponent();



}
  /// <summary>
/// Invoked when this page is about to be displayed in a Frame.
/// </summary>
/// <param name="e">Event data that describes how this page was reached. The Parameter
/// property is typically used to configure the page.</param>
protected override void OnNavigatedTo(NavigationEventArgs e)



{

}
  private void Button_Click_1(object sender, RoutedEventArgs e)



{
  label1.Text = "Hello world!";



}

}

}  

Output

MessageBox Class in Windows Form

MessageBox class is used to display informative messages to users. A message box can contains text, buttons and symbols. One cannot create a new instance of this class something like other classes. To display a message you need to call show() method of this class. It is a static method and accepts text, title, buttons, icons and etc. as per desired parameters.


To show a simple message to the user:
MessageBox.Show("This is My First Message");

And it will provide a message box as in following image

Show method have some overloads, we will use a standard overload that is mostly used in programming.

MessageBox.Show("This is My First Message","Title",
MessageBoxButtons.OKCancel,MessageBoxIcon.Information);

A message box will show like the following image.

In the above show method the first parameter is text to be shown, second parameter is the captions or title of the box, third parameter is the messageBox buttons (here OkCancel) and fourth parameter is the icon(here information icon) to be shown. There are some more buttons and icons to be used in this method which are:

MessageBox buttons which are in enumeration MessageBoxButtons

• AbortRetryIgnore: contains Abort, Retry and Ignore button.
• Ok: contains ok button.
• OkCancel: contains Ok and Cancel button.
• RetryCancel: contains Retry and Cancel button.
• YesNo: contain Yes and No buttons.
• YesNoCancel: contains Yes, No and Cancel buttons.

Message box icons which are in enumeration MessageBoxIcons

• Asterisk: symbol consisting a letter ‘l’ within a circle.
• Error: symbol consisting a letter ‘X’ within a white circle and red background.
• Exclamation: symbol consisting an exclamation mark within a rectangle.
• Hand: symbol consisting a white ‘X’ within a circle.
• Information: symbol consisting a letter ‘i’ within a circle.
• None: contains no symbol.
• Question: symbol consisting a question mark within a circle.
• Stop: symbol consisting a white X within a circle.
• Warning: symbol consisting a exclamation point within a triangle.

Here are some more overloads of Show() method.

MessageBox.Show("Text");

MessageBox.Show("Text", "Title");

MessageBox.Show("Text", "Title", MessageBoxButtons.OK);

MessageBox.Show("This is My First Message", "Title", MessageBoxButtons.OKCancel, MessageBoxIcon.Error);

We can set default button of the box, enable options of message box, enable of disable help button and etc.as per our requirements.

Status Strip Control
Error Provider Control